This invention relates generally to cutting processes and more particularly to utilizing high-velocity jets of liquid or an abrasive laden liquid to shred solid material including metal.
An important application of large capacity shredding equipment is in processing solid waste streams. These streams contain mostly solid material, but may contain liquids, particularly in containers. In some cases the liquids may be volatile and flammable. Frequently the shredding operation is performed to process the waste stream for incineration.
Existing equipment for shredding a heterogeneous stream, containing solid material or mixed solid and liquid material, generally uses hardened and/or corrosion resistant steel cutting tools. During the shredding operation, sparks can be produced when the cutting tools strike hard objects. Therefore there is a fire hazard, and in the presence of volatile flammable liquids, an explosion hazard. These hazards can be overcome by immersing the shredding operation in water, but this requires that the stream first be dried if it is t be subsequently incinerated.
The metals used in the steel alloys of the cutting tools can be worn off in the shredding operation. If the stream is subsequently input into an incinerator to be incinerated, some of the metals can appear in the incinerator stack gas as air pollutant emissions. In some comparisons of emissions between incinerators which do and do not have shredding of the input stream, the emissions are generally comparable except for much higher emissions of beryllium, chromium, and nickel from those that had shredding of the input stream. These metals may also appear in the incinerator ash, making the ash more toxic.
The foregoing illustrates limitations known to exist in present devices. Thus, it is apparent that it would be advantageous to provide an alternative directed to overcoming one or more of the limitations set forth above. Accordingly, a suitable alternative is provided including features more fully disclosed hereinafter.